adjective Lacking even the smallest amount of money.
In societies without national insurance of any kind, almshouses are the last refuge of penniless people.
adjective Of a country's system of money, abstaining from the use of penny coins, despite having fully decimalized currency, by means of rounding of cash transactions (but not necessarily of cashless ones).
Canada became a penniless country in 2013 simply by rounding its cash transactions to the nearest nickel but otherwise not changing anything.